Battle of Langshan Jiang

The Battle of Langshan Jiang (919 CE) was a battle between Wuyue and Southern Wu during the Five Dynasties and Ten Kingdoms period of China. The Wuyue used a fire attack to destroy the Wu navy, destroying 400 out of 500 Wu vessels and capturing 7,000 Wu troops.

Background
The Wuyue state planned to reunite China and win great glory for their ruler Qian Liu. The invasion was to take place near the Langshan (Wolf Mountain) on the northern shores of the Yangtze River, where Qian Yuanguan quickly built a fleet of small war vessels, having modified fishing and trade ships. The Southern Wu, however, got word of the river invasion and sent their best commander, Peng Yanzhang, to protect the river at all costs. Resources were scarce, so technology and innovation would play a major role in the battle. Outnumbered and in hostile territory, Qian Yuanguan needed to be creative and work quickly to succeed. Qian Liu planned to build a grandiose temple on the banks of the Yangtze River, and Wuyue had to gain the support of the local populace. If Wuyue could build the temple, the people would see the power of Wuyue and leave Wu; the Wolf Mountain River became the site of a major battle between the two states.

Battle
The Wuyue navy of Qian Yuanguan, with fireships at the vanguard, attacked the Wu navy on the Langshan Jiang, with several Wu ships being destroyed by Wuyue fire ships. Other Wuyue ships, equipped with flamethrowers, used these technologies to destroy Wu vessels in battle at the first blockade of the river. After this first battle, the Wuyue gained control of a coastal village, and they built up forces in that village so that they could destroy Wu outposts along the banks. The Wuyue discovered that some rocks were coated with oil, and they utilized them for a fire attack. The Wu navy was devastated, and the Wuyue army launched an assault on the Wu Army to the south of their village while also building a temple on the shore. Wuyue paid the river pirates 2,000 coins to join them as allies, and they gained the allegiance of another town by building a temple. Wuyue destroyed the main Wu Navy castle, forcing Peng Yanzhang's army to retreat. Yanzhang committed suicide, and the Wu army retreated. 400 Wu ships were destroyed and 7,000 troops captured by Wuyue, and Qian Liu sent his son to continue the invasion of Wu.